iSpring Free - iSpring Free is a free eLearning authoring tool that allows you to create responsive courses and quizzes right in PowerPoint and convert them to HTML5 or SCORM.
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.
H5P - H5P is a free and open-source content collaboration framework based on JavaScript.
Sli.do - Slido is the ultimate Q&A and polling platform for live and virtual meetings and events. It offers interactive Q&A, live polls and insights about your audience.
Articulate Storyline - Articulate Storyline is a program that allows you to create interactive courses of any kind with templates and a simple system. There is a free trial offered so that you can determine whether you want to use the program further or not.
Mentimeter - a web-based polling tool for workshops, conferences & events